For simplicity's purpose the present invention will be described in association with a specific form of breathing device, namely an aviator's mask. However, the principles of this invention can be applied to other breathing devices such as, for example gas masks of the type worn by ground troops during a gas attack.
One of the problems associated with breathing devices of the type referred to is the collection of effluents within the mask. Such effluents can be vomit, sweat, or mucous products. As the mask is customarily sealed about the face of the wearer to prevent either the ingress of ambient gases or the egress of breathing gases, the wearer's effluents will accumulate in the mask. The accumulated effluents could initially cause discomfort to the wearer and may subsequently jeopardize the proper functioning of some of the components of the mask, such as the exhalation valve. In the commonly used aviator's masks or infantry gas masks of today the only practical way such effluents can be discharged is by pulling the mask away from the face, thereby breaking the mask seal, and letting the effluents drain out between the mask and the face. There are several fundamental disadvantages to this practice. Thus, the effluents are free to enter the environment of the wearer, which may be the cockpit of an aircraft, causing subsequent fouling of the wearer's environment as well as the apparel of the wearer. Additionally, breaking the face seal of the mask may compromise the safety of the wearer if the atmosphere external to the mask is not suitable for breathing as would be the case if the atmosphere contained lethal gases, such as nerve gases, or similarly, if the atmosphere contained insufficient oxygen for breathing purposes.
The prior art has recognized some of the problems set forth above. In U.S. Pat. No. 3,473,165 a space suit is disclosed having a venting device associated therewith. This device serves several purposes such as venting or purging the interior of the helmet, for feeding, or for collecting effluents externally in a disposable receiver. Thus, the face mask of a pressure suit is provided with a valve housing provided with a port which can be disposed in various positions depending upon the desired operation. Disposed on the inside of the face mask adjacent the mouth of the wearer is a funnel-like mouthpiece which is in turn secured to the housing, the mouthpiece also being provided with a valve. Finally, for collecting effluents a pouch may be secured to an external portion of the valve housing by a snap ring. While this device does provide for the encapsulation of effluents exterior of the mask for subsequent disposal, it utilizes a relatively expensive and unduly complex valving arrangement which cannot be readily cleaned after use. Also, the particular device is designed primarily for receiving vomit and other effluent products discharged from the mouth and it cannot readily receive mucous from the nasal/oral cavities or sweat. It is also possible that the valve housing can be improperly manipulated by the operator causing the system to be open to the external atmosphere.
Another device is shown in U.S. Pat. No. 2,444,417 which discloses an oxygen mask having an inlet and an outlet. The mask is also provided with a further port and the patent discloses that any condensation formed within the mask will tend to collect in a reservoir formed in the neighborhood of the port. Should the amount of condensation become too great, it could be drained through the port by flexing the port until its recess is so distorted as to provide a connection from the reservoir to the atmosphere. A somewhat similar device is shown in U.S. Pat. No. 2,005,072 which is provided with a pair of one-way valves through which effluents may be discharged. While both of the above two devices are relatively simple, neither one provides an effluent receiver which can be utilized to prevent the soiling of the wearer's apparel and/or environment. Furthermore, in the first of the two devices there is no provision for an entirely closed system which would prevent the ingress of atmospheric air into the breathing cavity.